From ee2aa85f444d81395c15b63f6e361721536f7df6 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Sun, 17 Aug 2008 08:07:31 +0000 Subject: [PATCH] Revert 54821. It's miscompiling 252.eon and 447.dealII git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54878 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopStrengthReduce.cpp | 119 +------------------ 1 file changed, 1 insertion(+), 118 deletions(-) diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 40bbe95f7e9..04faa0aa508 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -45,7 +45,6 @@ STATISTIC(NumReduced , "Number of GEPs strength reduced"); STATISTIC(NumInserted, "Number of PHIs inserted"); STATISTIC(NumVariable, "Number of PHIs with variable strides"); STATISTIC(NumEliminated , "Number of strides eliminated"); -STATISTIC(NumShadow , "Number of Shadow IVs optimized"); namespace { @@ -178,13 +177,8 @@ private: IVStrideUse* &CondUse, const SCEVHandle* &CondStride); void OptimizeIndvars(Loop *L); - - /// OptimizeShadowIV - If IV is used in a int-to-float cast - /// inside the loop then try to eliminate the cast opeation. - void OptimizeShadowIV(Loop *L, ICmpInst *Cond, - const SCEVHandle *&CondStride); bool FindIVUserForCond(ICmpInst *Cond, IVStrideUse *&CondUse, - const SCEVHandle *&CondStride); + const SCEVHandle *&CondStride); bool RequiresTypeConversion(const Type *Ty, const Type *NewTy); unsigned CheckForIVReuse(bool, bool, const SCEVHandle&, IVExpr&, const Type*, @@ -1695,115 +1689,6 @@ ICmpInst *LoopStrengthReduce::ChangeCompareStride(Loop *L, ICmpInst *Cond, return Cond; } -/// OptimizeShadowIV - If IV is used in a int-to-float cast -/// inside the loop then try to eliminate the cast opeation. -void LoopStrengthReduce::OptimizeShadowIV(Loop *L, ICmpInst *Cond, - const SCEVHandle *&CondStride) { - - const SCEVConstant *SC = dyn_cast(*CondStride); - if (!SC) return; - - SCEVHandle IterationCount = SE->getIterationCount(L); - if (isa(IterationCount)) - return; - - for (unsigned Stride = 0, e = StrideOrder.size(); Stride != e; - ++Stride) { - std::map::iterator SI = - IVUsesByStride.find(StrideOrder[Stride]); - assert(SI != IVUsesByStride.end() && "Stride doesn't exist!"); - - for (std::vector::iterator UI = SI->second.Users.begin(), - E = SI->second.Users.end(); UI != E; /* empty */) { - std::vector::iterator CandidateUI = UI; - UI++; - Instruction *ShadowUse = CandidateUI->User; - const Type *DestTy = NULL; - - /* If shadow use is a int->float cast then insert a second IV - to elminate this cast. - - for (unsigned i = 0; i < n; ++i) - foo((double)i); - - is trnasformed into - - double d = 0.0; - for (unsigned i = 0; i < n; ++i, ++d) - foo(d); - */ - UIToFPInst *UCast = dyn_cast(CandidateUI->User); - if (UCast) - DestTy = UCast->getDestTy(); - else { - SIToFPInst *SCast = dyn_cast(CandidateUI->User); - if (!SCast) continue; - DestTy = SCast->getDestTy(); - } - - PHINode *PH = dyn_cast(ShadowUse->getOperand(0)); - if (!PH) continue; - if (PH->getNumIncomingValues() != 2) continue; - - const Type *SrcTy = PH->getType(); - int Mantissa = DestTy->getFPMantissaWidth(); - if (Mantissa == -1) continue; - if ((int)TD->getTypeSizeInBits(SrcTy) > Mantissa) - continue; - - unsigned Entry, Latch; - if (PH->getIncomingBlock(0) == L->getLoopPreheader()) { - Entry = 0; - Latch = 1; - } else { - Entry = 1; - Latch = 0; - } - - ConstantInt *Init = dyn_cast(PH->getIncomingValue(Entry)); - if (!Init) continue; - ConstantFP *NewInit = ConstantFP::get(DestTy, Init->getZExtValue()); - - BinaryOperator *Incr = - dyn_cast(PH->getIncomingValue(Latch)); - if (!Incr) continue; - if (Incr->getOpcode() != Instruction::Add - && Incr->getOpcode() != Instruction::Sub) - continue; - - /* Initialize new IV, double d = 0.0 in above example. */ - ConstantInt *C = NULL; - if (Incr->getOperand(0) == PH) - C = dyn_cast(Incr->getOperand(1)); - else if (Incr->getOperand(1) == PH) - C = dyn_cast(Incr->getOperand(0)); - else - continue; - - if (!C) continue; - - /* Add new PHINode. */ - PHINode *NewPH = PHINode::Create(DestTy, "IV.S.", PH); - - /* create new icnrement. '++d' in above example. */ - ConstantFP *CFP = ConstantFP::get(DestTy, C->getZExtValue()); - BinaryOperator *NewIncr = - BinaryOperator::Create(Incr->getOpcode(), - NewPH, CFP, "IV.S.next.", Incr); - - NewPH->addIncoming(NewInit, PH->getIncomingBlock(Entry)); - NewPH->addIncoming(NewIncr, PH->getIncomingBlock(Latch)); - - /* Remove cast operation */ - ShadowUse->replaceAllUsesWith(NewPH); - ShadowUse->eraseFromParent(); - SI->second.Users.erase(CandidateUI); - NumShadow++; - break; - } - } -} - // OptimizeIndvars - Now that IVUsesByStride is set up with all of the indvar // uses in the loop, look to see if we can eliminate some, in favor of using // common indvars for the different uses. @@ -1831,8 +1716,6 @@ void LoopStrengthReduce::OptimizeIndvars(Loop *L) { if (!FindIVUserForCond(Cond, CondUse, CondStride)) return; // setcc doesn't use the IV. - OptimizeShadowIV(L, Cond, CondStride); - // If possible, change stride and operands of the compare instruction to // eliminate one stride. Cond = ChangeCompareStride(L, Cond, CondUse, CondStride); -- 2.34.1